Siebert



March 10, 1964 A, SEBEFQT 3,124,315

FEED HOPPER FOR FINE GRINDING ROLLER MILLS Filed Sept. 25, 1961 2 Sheets-Sheet 1 IN VE N T04 ALFRED $155512? March 10, 1964 A. SIEBERT 3,124,315

FEED HOPPER FOR FINE GRINDING ROLLER MILLS Filed Sept. 25,1961 2 Sheets-Sheet 2 "we/dram ALFREO 5/EBERT United States Patent 3,124,315 FEED HOPPER FOR FINE GRINDING ROLLER MILLS Alfred Siehert, Niederuzwil, Switzerland, assign'or to Gebrueder Bnehler, Uzwil, Switzerland, a firm of Switzerland Filed Sept. 25, 1961, Ser. No. 140,274 Claims priority, application Switzerland Sept. 27, 1960 Qiaims. (Cl. 241-224) In fine grinding roller mills most feed hoppers consist of adjustable lateral sealing plates and one or two hopper walls disposed parallel to the axis of the grinding rollers.

Hitherto the hopper walls were screwed on to the sealing plates or clamped by means of tommy screws. However this type of fastening entails the disadvantage that under certain curcumstances the sealing plates, when locally locked, no longer fit tight on the entire face of the rollers. In case of hydraulic clamping means being used, automatic adjusting means for the sealing plates should be included. However, if the sealing plates are locked to the hopper walls they cannot move, thereby entailing leakages.

It is an object of this invention to provide means to avoid the above mentioned disadvantages. These disadvantages are overcome by providing a new feed hopper for fine grinding mills, comprising magnetic holding means for fastening the hopper walls to the sealing jaws.

One embodiment of this invention is shown by way of example in the accompanying drawings, wherein:

FIG. 1 is a sectional elevation of a roller mill along the line II of FIGURE 2.

FIG. 2 is a corresponding plane view.

FIG. 3 is a sectional side elevation along the line III-III of FIGURE 1.

FIG. 4 shows a detail of FIGURE 3 in an enlarged scale.

FIG. 5 is a sectional side elevation along the line VV of FIGURE 4, and

FIG. 6 is sectional view along the line VIVI of FIGURE 5.

As shown in FIGURES 1-3, the grinding rollers 2, 3, journalled in housing 1 are topped by a feed hopper consisting of two sealing plates 5 and two hopper walls 6. A hydraulic block comprising a piston 10 is disposed against housing 1. Piston 10 presses sealing plate 5 against shoulders 12 of the grinding rollers 2 and 3 and also bears holder 13. A second piston 14 pressing against a lever 15 pivotably mounted on a pivot pin 16 is disposed in block 9. Pivot pin 16 is mounted in two projecting lugs 17 forming part of holder 13. The force exerted by piston 14 will be transmitted by lever 15 to the edge 18 of a recess 19 in sealing plates 5 pressing this latter downward to rollers 2 and 3. Holder 13, provided with two lateral glide shoes 20 is guided by projecting guide tracks 21 on the sealing plate 5. The pistons are actuated by some fluid, preferably oil, supplied through pipes 22 and 23. Hopper wall 6 is held in place by magnetic holding fixtures 24 disposed on the outside of sealing plate 5.

As shown in FIGURES 4-6 the magnetic holders 24 consist of a permanent magnet 25 clamped by means of a clamping cap 27, 28 and a screw 30 against sealing plate 5 but spaced from this latter by a washer 26. Both,

3,124,315 Patented Mar. 10, 1964 "ice washer 26 and clamping caps 27, 28 consist of some nonmagnetic material, such as aluminum or the like. Clamping cap 27 is placed on projecting tetragonal member 29 disposed on sealing plate 5 and fastened by means of a screw 30. The tetragonal members 29 are designed and disposed in such a manner that the active faces 33 of the magnets 25 are flush with the edge of the sealing plate 5 and the hopper wall 6. Cap 28, basically similar to cap 27 is moreover provided with a locking tab 31 to prevent inadmissible displacement of hopper wall 6. The clamping caps 28 will normally be used on the upper magnets but can also replace the lower caps 27 as well.

The product to be ground will be fed into the feed hopper. In the above described arrangement the action of pistons 14 and 16 will automatically compensate any wear occurring on the sealing faces of plates 5 on account of their friction on the grinding rolls 2 and 3. The magnets readily admit vertical displacement of the hopper walls 6 since the magnetic forces acting in any direction parallel to the active surfaces 33 of the magnets 25 are negligible compared with those acting perpendicular to surfaces 33. It may also be added that washers 26 prevent the magnetic flux from being shunted through sealing plate 5 (FIG. 5) but is compelled to pass through hopper wall 6.

What I claim is:

1. In a material grinding mill including a pair of parallel axially rotatable rollers, each having a circumferential peripheral grinding surface, the peripheral grind ing surfaces being juxtaposed so that material fed between said juxtaposed surfaces can be ground by opposing rotations of the rollers, a hopper, for feeding the material between the juxtaposed surfaces, comprising: two longi tudinal walls, one wall being juxtaposed against one roller and longitudinally extending parallelly along the axis of rotation of the one roller, the other wall being juxtaposed against the other roller and longitudinally extending parallelly along the axis of rotation of the other roller; two side plates, said side plates being spaced apart and forming with said two walls said hopper, each side plate being disposed in juxtaposed relation with the rollers; and, magnet means for holding said plates and said walls together.

2. A hopper, according to claim 1, wherein said magnet means are mounted on said side plates in such a manner that the faces of said magnet means are flush with the edges of the plates.

3. A feeding hopper, according to claim 1, wherein clamping caps are employed to secure said magnet means on said plates.

4. A feeding hopper according to claim 3, wherein said clamping caps include a locking tab projecting beyond the plate and securing thereby the position of said walls.

5. A feeding hopper, according to claim 1, wherein said magnet means magnetically holds said walls to said plates and allows vertical movement of said walls.

References Cited in the file of this patent UNITED STATES PATENTS 1,024,168 Williams Apr. 23, 1912 2,519,435 Byrd Aug. 22, 1950 2,727,650 Moynihan Dec. 20, 1955 2,808,215 Bosshard Oct. 1, 1957 

1. IN A MATERIAL GRINDING MILL INCLUDING A PAIR OF PARALLEL AXIALLY ROTATABLE ROLLERS, EACH HAVING A CIRCUMFERENTIAL PERIPHERAL GRINDING SURFACE, THE PERIPHERAL GRINDING SURFACES BEING JUXTAPOSED SO THAT MATERIAL FED BETWEEN SAID JUXTAPOSED SURFACES CAN BE GROUND BY OPPOSING ROTATIONS OF THE ROLLERS, A HOPPER, FOR FEEDING THE MATERIAL BETWEEN THE JUXTAPOSED SURFACES, COMPRISING: TWO LONGITUDINAL WALLS, ONE WALL BEING JUXTAPOSED AGAINST ONE ROLLER AND LONGITUDINALLY EXTENDING PARALLELLY ALONG THE AXIS OF ROTATION OF THE ONE ROLLER, THE OTHER WALL BEING JUXTAPOSED AGAINST THE OTHER ROLLER AND LONGITUDINALLY EXTENDING PARALLELLY ALONG THE AXIS OF ROTATION OF THE OTHER ROLLER; TWO SIDE PLATES, SAID SIDE PLATES BEING SPACED APART AND FORMING WITH SAID TWO WALLS SAID HOPPER, EACH SIDE PLATE BEING DISPOSED IN JUXTAPOSED RELATION WITH THE ROLLERS; AND, MAGNET MEANS FOR HOLDING SAID PLATES AND SAID WALLS TOGETHER. 